Missing NJ Rabbinical Student in Israel

[iwishiwerethin]

If that is so, why is one supposed to sit shiva for someone who converts formally and becomes non-Jewish?

Because renouncing Judaism is a spiritual death. However, the apostate will still give din v'cheshban as a Jew, and does not have to go through the rigorous conversion process when he does tshuva.

[theflipflop]

Is it Halacha that we sit shiva for an apostate, or is that just a cultural thing?

I would think some good old fashioned shunning would do the trick. I wouldn't want to give the apostate the honor if sitting shiva for them.

[Woodrow LI]

It seems the OP has run it's course and the thread is drifting away. time to close the thread